Ferromagnetic superconductivity with excitonic Cooper pairs: Application to $\Gamma$-valley twisted semiconductors

Daniele Guerci; Liang Fu

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arXiv · 2503.05863

Ferromagnetic superconductivity with excitonic Cooper pairs: Application to $\Gamma$-valley twisted semiconductors

Daniele Guerci·Liang Fu

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Abstract

We present a theory of ferromagnetic superconductivity that emerges upon doping a correlated ferromagnetic insulator through the condensation of excitonic Cooper pairs, which are charge-$2e$ bosonic quasiparticles made of Cooper pairs strongly hybridized with excitons. By solving a model of spin-polarized electrons using the strong-coupling expansion to the second order, we demonstrate the emergence of excitonic Cooper pairs from electron-hole fluctuations upon doping a strongly correlated insulator. We characterize their binding energy, effective mass, and the resulting superconducting transition temperature. We propose possible realization of spin-polarized superconductivity in twisted semiconductors with honeycomb moir\'e superlattice.

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Daniele Guerci, Liang Fu. 2025-03-07. Ferromagnetic superconductivity with excitonic Cooper pairs: Application to $\Gamma$-valley twisted semiconductors. https://arxiv.org/abs/2503.05863

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